Potential antiviral agents: synthesis and conformational studies in the sugar series
2018-09-11T08:15:06Z (GMT) by
The structure of sugar oximes has been examined by nuclear magnetic resonance spectroscopy (NMR). There appears to be no simple relationship between the structure of the oxime and the ratio, on acetylation, of acetylated nitrile to acetylated oxime. The synthesis of thiazines, from thioamides and vinyl ketones, appears to have limited scope and was unsuccessful when applied to aldonothioamides. The synthesis of several 2-aldono-1,3-thiazoles is recorded. Other routes to nitrogen and sulphur-containing ring systems with sugar side chains have been investigated. Some of these compounds have been tested for microbiological activity. The structure of sugar imidazolines has been examined by NMR spectroscopy. The conformation of straight chain acetylated sugars is explained in terms of a simple model. The NMR measurements on several acyclic sugars are in accordance with this model. The method developed by Whiffen, relating conformation to optical rotation, has been extended to acetylated pyranoses by determining new values for Whiffen's rotation parameters. New parameters have been evaluated which make it possible to treat acyclic sugars by this method. Al though the assumptions made in this treatment limit the accuracy, it seems that optical rotation provides useful supporting evidence for conformation. In the final chapter, the results of a preliminary investigation into the reactions of organo-lithium compounds with carbohydrates are reported.